The helium burning during the core-WD merger in the CD scenario, and in rare cases in an LTP/VLTP, nucleosynthesises the radioactive isotope \(^{44}\) Ti, like helium burning in the DDet scenario (e.g., [1]}). In most SNe Ia according to the CD scenario, as I found above, LTP/VLTP does not take place. As well, most explosions take place more than a thousand years after merger. Because the radioactive isotope \(^{44}\) Ti has a half-life of 60 years I do not expect the presence of more \(^{44}\) Ti than what the explosion by deflagration to detonation transition predicts (see comparison between models by, e.g, [2]}).
Recent studies suggest that most SNe Ia contain small masses of \(^{44}\) Ti, as the deflagration to detonation transition predicts or less (e.g., [3]}, [4]}).
In rare cases the explosion takes place hundreds of years after merger. Then there might be some extra \(^{44}\) Ti. In these cases there is a close CSM because of the short delay from the CEE to explosion (short \(t_{\rm CEED}\) ).
In the very rare cases of LTP/VLTP that triggers a SN Ia or take place a short time before the SN Ia explosion, I expect to find a somewhat larger \(^{44}\) Ti mass than what the deflagration to detonation transition predicts.
